Chip cards are widely used in portable electronic devices, such as mobile phones, to enhance or specialize the functions of the portable electronic devices. Generally, the chip card is removed from a casing of the portable electronic device by a pin inserted through a pin hole of the casing to eject the chip card. However, electronic elements inside of the portable electronic device are easily damaged if outside contamination, such as water, vapor or dust enters the portable electronic device through the pin hole of the casing.